Delayed power-on function for an electronic device

ABSTRACT

A delayed power-on function for an electronic device is disclosed. A charging unit charges a rechargeable battery with a pre-charge current when a voltage of the rechargeable battery is less than a voltage threshold value and with a current larger than the pre-charge current when the voltage of the rechargeable battery is greater than the voltage threshold value. A disabling unit can disable power-on when the voltage of the rechargeable battery is less than the voltage threshold value. A user may also be notified when power-on is disabled.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims priority under 35 U.S.C. §119 to JapaneseApplication No. 2009-017016, filed on Jan. 28, 2009, entitled “MOBILEDEVICE” and Japanese Application No. 2010-003439, filed on Jan. 9, 2010,entitled “ELECTRONIC DEVICE, METHOD FOR PROVIDING A NOTIFICATION OF APOWER-ON/OFF STATE AND PROGRAM FOR PROVIDING A NOTIFICATION OF APOWER-ON/OFF STATE”. The contents of which are incorporated by referenceherein in their entirety.

FIELD

Embodiments of the present disclosure relate generally to electronicdevices, and more particularly relate to an electronic device with arechargeable battery.

BACKGROUND

Many electronic devices use rechargeable batteries that are availablefor repeated charge and discharge cycles. When the rechargeablebatteries are in an over-discharged condition, they may first bepre-charged with a low-current to ensure safety of the rechargeablebattery and to reduce degradation of the battery. After the low-currentpre-charge, the rechargeable battery is then charged with a quick chargehaving a larger current.

Pre-charge is generally performed when remaining battery life is short,and a voltage of the rechargeable battery is low. Under this condition,a capability of the rechargeable battery to supply current may be low.Therefore, if an electronic device such as a mobile phone is powered-onduring the pre-charge, the electronic device may soon be shut off forlack of power after disconnection from a charger. Accordingly, it ispreferable that no request for power-on be received by the electronicdevice during a low voltage charge such as a pre-charge.

Therefore, there is a need for enhanced usability during charging of arechargeable battery of an electronic device.

SUMMARY

A delayed power-on function for an electronic device is disclosed. Acharging unit charges a rechargeable battery with a pre-charge currentwhen a voltage of the rechargeable battery is less than a voltagethreshold value and with a current larger than the pre-charge currentwhen the voltage of the rechargeable battery is equal to or greater thanthe voltage threshold value. A disabling unit disables power-on when thevoltage of the rechargeable battery is less than the voltage thresholdvalue. A user may also be notified when power-on is disabled.

An embodiment comprises an electronic device. The electronic devicecomprises a rechargeable battery, and a charging unit. The charging unitis operable to charge the rechargeable battery with a pre-charge currentwhen a voltage of the rechargeable battery is less than a voltagethreshold value. The charging unit is further operable to charge therechargeable battery with a current that is larger than the pre-chargecurrent, when the voltage of the rechargeable battery is equal to orgreater than the voltage threshold value. The electronic device furthercomprises a disabling unit operable to disable power-on when the voltageof the rechargeable battery is less than the voltage threshold value.The electronic device also comprises a notifying unit operable toprovide a power-on disabled notification, if the rechargeable battery isbeing charged with the pre-charge current and the pre-charge current isequal to or greater than a current threshold value.

An embodiment comprises a method for charging an electronic device. Themethod comprises charging a rechargeable battery with a pre-chargecurrent when a voltage of the rechargeable battery is less than avoltage threshold value, and charging the rechargeable battery with acurrent that is larger than the pre-charge current, when the voltage ofthe rechargeable battery is equal to or greater than the voltagethreshold value. The method further comprises disabling power-on whenthe voltage of the rechargeable battery is less than the voltagethreshold value. The method also comprises providing a power-on disablednotification, if the rechargeable battery is being charged with thepre-charge current and the pre-charge current is equal to or greaterthan a current threshold value.

An embodiment comprises a computer-readable medium for an electronicdevice. The computer-readable medium comprises program code for charginga rechargeable battery with a pre-charge current when a voltage of therechargeable battery is less than a voltage threshold value and chargingthe rechargeable battery with a current that is larger than thepre-charge current, when the voltage of the rechargeable battery isequal to or greater than the voltage threshold value. Thecomputer-readable medium further comprises program code for disablingpower-on when the voltage of the rechargeable battery is less than thevoltage threshold value. The computer-readable medium also comprisesprogram code for providing a power-on disabled notification, if therechargeable battery is being charged with the pre-charge current andthe pre-charge current is equal to or greater than a current thresholdvalue.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the present disclosure are hereinafter described inconjunction with the following figures, wherein like numerals denotelike elements. The figures are provided for illustration and depictexemplary embodiments of the present disclosure. The figures areprovided to facilitate understanding of the present disclosure withoutlimiting the breadth, scope, scale, or applicability of the presentdisclosure. The drawings are not necessarily made to scale.

FIG. 1 is an illustration of an exemplary external view of a mobiletelephone according to an embodiment of the disclosure.

FIG. 2 is an illustration of an exemplary functional block diagram of acharge and discharge control system of the mobile telephone shown FIG.1.

FIG. 3A is an illustration of a schematic structure of a connectionterminal used for connection with a Micro-Universal Serial Bus(Micro-USB) compliant cable.

FIG. 3B is an illustration of schematic structures of a connectionterminal used for connection with a Micro-USB compliant cable, and anadapter cable used for an AC adapter.

FIG. 3C is an illustration of schematic structures of a connectionterminal used for connection with a Micro-USB compliant cable, and astructure of a Universal Serial Bus (USB) cable used for a PC.

FIG. 4 is an illustration of an exemplary detailed functional blockdiagram of a system unit of the charge and discharge control systemshown in FIG. 1.

FIG. 5 is an illustration of a flow diagram showing an exemplaryconnection detection process for charging a mobile telephone accordingto an embodiment of the disclosure.

FIG. 6 is an illustration of a flow diagram showing an exemplarypre-charge process using an electrical outlet (wall connection), forcharging a mobile telephone according to an embodiment of thedisclosure.

FIG. 7 is an illustration of a flow diagram showing an exemplarypre-charge process using a USB connection for charging a mobiletelephone according to an embodiment of the disclosure.

FIG. 8 is an illustration of a flow diagram showing an exemplary quickcharge process for charging a mobile telephone according to anembodiment of the disclosure.

FIG. 9A is an illustration of an exemplary display content on a screenof a display unit according to an embodiment of the disclosure.

FIG. 9B is an illustration of an exemplary display content on a screenof a display unit according to an embodiment of the disclosure.

FIG. 10 is an illustration of an exemplary state transition diagram forcharging a mobile telephone corresponding to the flow diagram of FIG. 6.

FIG. 11 is an illustration of an exemplary state transition diagram forcharging a mobile telephone corresponding to the flow diagram of FIGS. 7and 8.

FIG. 12 is an illustration of a graph showing an exemplary relationshipbetween a rechargeable battery voltage (VBAT) and time when a statevariable ST has a value of WALL (0, 2, 3) according to an embodiment ofthe disclosure.

FIG. 13 is an illustration of a graph showing an exemplary relationshipbetween VBAT and time when ST has a value of USB (0-3) according to anembodiment of the disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

The following description is presented to enable a person of ordinaryskill in the art to make and use the embodiments of the disclosure. Thefollowing detailed description is exemplary in nature and is notintended to limit the disclosure or the application and uses of theembodiments of the disclosure. Descriptions of specific devices,techniques, and applications are provided only as examples.Modifications to the examples described herein will be readily apparentto those of ordinary skill in the art, and the general principlesdefined herein may be applied to other examples and applications withoutdeparting from the spirit and scope of the disclosure. Furthermore,there is no intention to be bound by any expressed or implied theorypresented in the preceding technical field, background, brief summary orthe following detailed description. The present disclosure should beaccorded scope consistent with the claims, and not limited to theexamples described and shown herein.

Embodiments of the disclosure are described herein in the context of onepractical non-limiting application, namely, a mobile phone. Embodimentsof the disclosure, however, are not limited to such mobile phones, andthe techniques described herein may also be utilized in otherapplications. For example, embodiments may be applicable to digitalcameras, electronic game machines, digital music players, personaldigital assistance (PDA), personal handy phone system (PHS), lap topcomputers, tablet personal computer (tablet PC), and the like.

As would be apparent to one of ordinary skill in the art after readingthis description, these are merely examples and the embodiments of thedisclosure are not limited to operating in accordance with theseexamples. Other embodiments may be utilized and structural changes maybe made without departing from the scope of the exemplary embodiments ofthe present disclosure.

FIG. 1 is an illustration of an exemplary external view of a mobiletelephone 1 according to an embodiment of the disclosure. The mobiletelephone 1 comprises a foldable casing 2 comprising an upper part and alower part, a display unit 4 located on the upper part, and an operationkey unit 6 located on the lower part.

The display unit 4 may be a liquid crystal display (LCD) comprising ascreen for displaying various kinds of information. The display unit 4may be, for example but without limitation, a liquid crystal displaypanel (LCD) comprising a screen with about 3-inches width.

The operation key unit 6 comprises operation keys such as dial keys 8,at least one power key 10, and a functional key group 12. The dial keys8 are used for inputting, for example but without limitation, atelephone number, a text message, and the like. The power key 10 is usedfor turning power on or off to the mobile phone 1. The power may beturned on or off by activation or pressing and holding the power key 10down for a short time, such as for about one second. The power key 10 isalso used for ending a call in progress and for terminating an activity.The functional key group 12 comprises a cursor key 13 for moving acursor up or down and right or left, and a function key 14 for bringingup a function, such as a mail, a camera, or a telephone conversationfunction. Each of the operation keys may be made of, for example butwithout limitation, transparent resin material, and the like. Anembedded key light-emitting diode (LED) may be suitably located in eachof the operation keys for illuminating each of the operation keys.

FIG. 2 is an illustration of an exemplary functional block diagram of acharge and discharge control system 200 of the mobile telephone 1. Thecharge and discharge control system 200 comprises a connection terminal20, a rechargeable battery 22, a system power unit 24, a charge anddischarge control unit 30, and a system unit 50. The connection terminal20 is a terminal for connection with a Micro-Universal Serial Bus(Micro-USB) compliant cable and is located on at least one side of thecasing 2 (FIG. 1). The connection terminal 20 can be connected to analternating-current (AC) adapter 102 through an adapter cable 101compliant with the Micro-USB and to a personal computer (PC) 104 througha Universal Serial Bus (USB) cable 103.

The rechargeable battery 22 can repeat charge and discharge cycles. Therechargeable battery 22 may be, for example but without limitation, alithium-ion battery, or the like.

The system power unit 24 supplies voltages having various voltage valuesrequired for driving the system unit 50.

24

50

The charge and discharge control unit (charging unit) 30 comprises aninput detector 32, an input transistor (TR) controller 34, a batteryField Effect Transistor (FET) controller 36, a battery level monitor 38,an analog-to-digital (A/D) converter 40, a pre-charge circuit 42, and acontroller 44.

The input detector 32 detects an input (connection) of a cable to theconnection terminal 20. The input TR controller 34 switches between ONand OFF states of an input TR 35 such that the input TR 35 is set at anON state while the input detector 32 detects the input and at an OFFstate while the input detector 32 does not detect the input. The batteryFET controller 36 switches between ON and OFF states of a battery FET37. The battery FET controller 36 sets the battery FET 37 at an ON statefor quick charge and at an OFF state for pre-charge, i.e., first andsecond pre-charge.

The battery-level monitor 38 supplies a voltage level to the controller44. The voltage level represents a voltage of the rechargeable battery22 converted by the analog-to-digital (A/D) converter 40.

The pre-charge circuit 42 supplies a pre-charge current to therechargeable battery 22. The pre-charge current has a constant value,such as 40 mA or 80 mA, received from an external power supply. Thecontroller 44 comprises a read-only memory (ROM) storing a chargecontrol program, a central processing unit (CPU) for executing aprogram, and a random-access memory (RAM) serving as a work area for aprogram and controls the functional blocks of the charge and dischargecontrol unit 30. The controller 44 also manages a state variable (ST)indicating a state of charge on the RAM.

As described above, at least two kinds of cables, the adapter cable 101for the AC adapter 102 and the USB cable 103 for the PC 104, areconnectable to the connection terminal 20. The determination of whichcable is connected to the connection terminal 20 can be made in thefollowing way.

FIG. 3A is an illustration of a schematic structure of a connectionterminal 20 used for connection with a Micro-Universal Serial Bus(Micro-USB) compliant cable. FIG. 3B is an illustration of schematicstructures of a connection terminal used for connection with a Micro-USBcompliant cable, and an adapter cable used for an AC adapter. FIG. 3C isan illustration of schematic structures of a connection terminal usedfor connection with a Micro-USB compliant cable, and a structure of aUSB cable used for a PC.

As illustrated in FIG. 3A, the connection terminal 20 comprises a VBUSterminal, a pair of data lines D+ and D−, and a ground terminal GND.Similarly, as illustrated in FIGS. 3B and 3C, each of the adapter cable101 for the AC adapter 102 and the USB cable 103 comprises a VBUSterminal, a pair of data lines D+ and D−, and a ground terminal GND. Thepair of data lines D+ and D− of the adapter cable 101 are coupledtogether in a loopback fashion. In contrast, the pair of data lines D+and D− of the USB cable 103 are not coupled together in a loopbackfashion.

After the input detector 32 detects connection of a cable to theconnection terminal 20, the data line D− may become high. When a highsignal is input into the data line D+ of the connection terminal 20, ifthe data line D− also becomes high, it can be determined that theconnection terminal 20 is connected to the adapter cable 101 for the ACadapter 102. In contrast, even when a high signal is input into the dataline D+ of the connection terminal 20, if the data line D− does notbecome high, it can be determined that the connection terminal 20 isconnected to the USB cable 103.

FIG. 4 is an illustration of an exemplary detailed functional blockdiagram of a system unit 400 (system unit 50) of the charge anddischarge control system 200 shown in FIG. 2. The system unit 400comprises a display controller 52, an operation receiving section 54, akey LED controller 56, a power-on section 58, a power-on disablingsection 60 (disabling unit 60), a wireless communication section 62, asystem controller 64 (notifying unit 64), a system interface (I/F) 66,and a USB interface (I/F) 68.

The display controller 52 controls a display content appearing on ascreen of the display unit 4. The operation receiving section 54receives a key operation from the operation key unit 6. The key LEDcontroller 56 controls the light emission of the key LED located on thebottom of each of the operation keys.

The power-on section 58 powers the mobile telephone 10N when theoperation receiving section 54 receives an activation or a long press ofabout 1 second on the power key 10 in a power-off state. The mobiletelephone 1 is brought into a normal usage state when it is beingpowered on. In the normal usage state, functions such mail function,camera function, and telephone-conversation function are available.Functions of the mobile telephone 1 that require a large current, suchas using a wireless circuit, are made available by power-on.

The power-on disabling section 60 causes a disabled state by disablingthe power-on caused by the power-on section 58. During the disabledstate, even if the power key 10 receives an activation or a long pressof about 1 second on the power key 10 in a power-off state, the mobiletelephone 1 is not powered on. The power-on disabling section 60 cancelsan input signal from the power key 10 during the disabled state, therebydisabling power-on caused by the power-on section 58. That is, in thisembodiment, the disabling power-on may be performed in software.However, in an embodiment, the disabling power-on may be performed inhardware. For example, the power-on disabling section 60 or othersuitable key controllers may block or disable a power-on signal orvoltage from the power key 10 thereby disabling power-on caused by thepower-on section 58. In this manner, disabling power-on may be performedusing hardware.

The wireless communication section 62 may comprise, for example, aradio-frequency wireless communication circuit. The wirelesscommunication section 62 can perform a telephone conversation function,a mail function, and the like of the mobile telephone 1 by communicatingwith a base station via their respective antennas through a wirelesscommunication channel.

The system controller 64 comprises a ROM for storing a system controlprogram, a CPU for executing a program, and a RAM serving as a work areafor a program and controlling the system unit 400.

The system I/F 66 is an interface for use in exchanging data with thesystem power unit 24 and the charge and discharge control unit 30. Thesystem controller 64 controls the system 400 based acquired informationacquired through the system I/F 66. The acquired information maycomprises, for example but without limitation, a presence/absence ofconnection detected by the input detector 32, a state of charge(pre-charge or quick charge), the voltage level of the battery levelmonitor 38 as needed, and the like.

The USB I/F 68 is a circuit for transmitting and receiving USB data.

FIGS. 5 to 8 are flow diagrams that illustrate processes 500-800 forcharging of the mobile telephone 1 according to various embodiments ofthe disclosure. FIG. 5 is an illustration of a flow diagram showing anexemplary connection detection process 500 for charging a mobiletelephone 1. FIG. 6 is an illustration of a flow diagram showing anexemplary pre-charge process 600 in a case of a Wall connection forcharging the mobile telephone 1. FIG. 7 is an illustration of a flowdiagram showing an exemplary pre-charge process 700 when a USBconnection used for charging the mobile telephone 1. FIG. 8 is anillustration of a flow diagram showing an exemplary quick charge process800 for charging the mobile telephone 1.

The various tasks performed in connection with processes 500-800 may beperformed by software, hardware, firmware, a computer-readable mediumhaving computer executable instructions for performing the processmethod, or any combination thereof. The processes 500-800 may berecorded in a computer-readable medium such as a semiconductor memory, amagnetic disk, an optical disk, and the like, and can be accessed andexecuted, for example, by a computer CPU in which the computer-readablemedium is stored. It should be appreciated that processes 500-800 mayinclude any number of additional or alternative tasks, the tasks shownin FIGS. 5-8 need not be performed in the illustrated order, andprocesses 500-800 may be incorporated into a more comprehensiveprocedure or process having additional functionality not described indetail herein. For illustrative purposes, the following description ofprocesses 500-800 may refer to elements mentioned above in connectionwith FIGS. 1-4. In practical embodiments, portions of processes 500-800may be performed by different elements of the charge and dischargecontrol system 200, for charging/discharging the mobile telephone 1,e.g., the connection terminal 20, the rechargeable battery 22, thesystem power unit 24, the charge and discharge control unit 30, thesystem unit 50, etc.

In the processes 500-800, voltage level of the battery level monitor 38is referred to as the rechargeable battery voltage VBAT, and voltagethreshold values of the VBAT are, for example but limitation, about 3.2V and about 2.8 V for the wall connection (WALL) and the USB connectionsrespectively.

Process 500 may begin by the input detector 32 detecting a connection ofa cable to the connection terminal 20 (YES branch of inquiry task S11),the system controller 64 acquires a signal indicating the detection fromthe controller 44 via the system interface (I/F) 66 and causes thepower-on disabling section 60 to disable power-on (Task S13).

Then, the input detector 32 determines whether the connection terminal20 is connected to the adapter cable 101 for the AC adapter 102 (i.e.,from an electrical outlet or wall connection) or to the USB cable 103(USB connection) (Inquiry task S14). The determination is made utilizingthe difference between the presence of the loopback connection of D+ andD− in the case of the adapter cable 101 and the absence thereof in thecase of the USB cable 103, as described above (FIG. 3).

If it is determined that a wall connection (i.e., an electrical outletis a power source) is detected (WALL branch of the inquiry task S14),the controller 44 changes ST to WALL0 (Task S25) and reads the VBAT(Task S21 in FIG. 6). If ST is WALL0 (WALL0 branch of inquiry task S22)and the VBAT is equal to or greater than 0 and less than 3.2 V(0≦VBAT<3.2 V branch of inquiry task S23), the controller 44 startspre-charge the rechargeable battery 22 with a first pre-charge currentof about 80 mA (Task S24).

The system controller 64 causes the display controller 52 to showcontent of display A shown in FIG. 9A on the screen of the display unit4 (Task S25) to provide a power-on disabled notification. The controller44 changes ST from WALL0 indicating an initial state to WALL2 indicatinga state of the first pre-charge (Task S26).

If it is determined that the VBAT is not less than 3.2 V (3.2 V VBATbranch of inquiry task S23), the controller 44 does not perform thefirst pre-charge. The system controller 64 causes the display controller52 to display content of display B shown in FIG. 9B on the screen of thedisplay unit 4 (Task S27). The controller 44 changes ST from WALL0indicating an initial state to WALL3 indicating a state of a quickcharge (Task S28).

If ST is WALL2 (WALL2 branch of inquiry task S22) and VBAT is equal toor greater than 0 and less than 3.2 V (0≦VBAT<3.2 V branch of inquirytask S29), process 600 leads back to task S22, and the first pre-chargecontinues. When the VBAT reaches a voltage level equal to or greaterthan 3.2 V by the first pre-charge (3.2 V VBAT branch of inquiry taskS29), the controller 44 completes the first pre-charge (Task S30). Thesystem controller 64 causes the display controller 52 to change thedisplay content from the display A to the display B (Task S31). Thecontroller 44 changes ST from WALL2 to WALL3 (Task S32).

After changing the state to WALL3 (Tasks S28 and S32), the controller 44turns the battery FET 37 ON (Task S33) and starts a quick charge (TaskS34). Charge current used for the quick charge current may be, forexample but without limitation, about 500 mA and the like.

The system controller 64 then acquires the state WALL3 from thecontroller 44, and deactivates the power-on disabling section 60 suchthat reception of the power key operation is enabled (Task S35). In thismanner, the power-on section 58 is enabled to receive a request forpower-on via the power key operation.

A charge process using the USB connection is described below.

As illustrated in FIG. 5, when the input detector 32 determines that USBconnection is detected (USB branch of inquiry task S14), the controller44 changes ST to USB0 and reads the VBAT (Task S41 in process 700).Then, if ST is USB0 (USB0 branch of inquiry task S42) and the VBAT isequal to or greater than 0 and less than 2.8 V (0≦VBAT<2.8 V branch ofinquiry task S43), the controller 44 starts the pre-charge with a secondpre-charge current of about 40 mA (Task S44). The controller 44 changesST from USB0 indicating an initial state to USB1 indicating a state ofsecond pre-charge (Task S45).

During the second pre-charge (0≦VBAT<2.8 V branch of inquiry task S43),the display unit 4 is not turned ON and no information is displayed onthe screen thereon. The USB specifications limit the capability of VBUScurrent supply from a host PC to a substantially maximum value of about100 mA. In an embodiment, even when the VBAT is low such that thecurrent is insufficient for displaying information on the screen of thedisplay unit 4, the pre-charge can be stably performed by not turning onthe display unit 4.

When the VBAT is equal to or greater than 2.8 V and less than 3.2 V (2.8V≦VBAT<3.2 V branch of inquiry task S43), the first pre-charge with acurrent of 80 mA (Task S46), the display A (Task S47), and changing STfrom USB0 to USB2 (Task S48) are performed. When the VBAT is equal to orgreater than 3.2 V (3.2 V VBAT branch of inquiry task S43), pre-chargeis not performed, and the content of the display B (Task S49) andchanging ST from USB0 to USB3 (Task S50) are performed. In this case,where the VBAT is relatively large, the battery FET 37 is turned ON(Task S68 in FIG. 8), and the quick charge with the current of 500 mA isperformed (Task S69 in FIG. 8).

When ST is USB1 (USB1 branch of inquiry task S42 in FIG. 7) and the VBATis equal to or greater than 0 and less than 2.8 V (0≦VBAT<2.8 V branchof inquiry task S51), the process 700 leads back to task S42. When VBATis equal to or greater than 2.8 V (2.8 V VBAT branch of inquiry taskS51), the first pre-charge with a current of 80 mA (Task S52),displaying the content of display A (Task S53), and changing ST fromUSB1 to USB2 (Task S54) are performed.

If ST is USB2 (USB2 branch of inquiry task S42) and the VBAT is equal toor greater than 0 V and less than 3.2 V (0≦V VBAT<3.2 V branch ofinquiry task S61 in FIG. 8, process 800 leads back to step S42 ofprocess 700. If ST is USB2 (USB2 branch of inquiry task S42) and theVBAT is equal to or greater than 3.2 V (3.2 V VBAT branch of inquirytask S61), no pre-charge is performed (Task S65) and presenting thecontent of the display B (Task S66) and changing ST from USB2 to USB3(Task S67) are performed.

When changing ST to the state USB3, the controller 44 performs a USBconnection process with the PC 104 (host PC) through the USB I/F 68 andrequests the PC 104 to increase the capability of VBUS current supplyfrom 100 mA to 500 mA. When the request is accepted, the controller 44turns the battery FET 37 ON and performs quick charge with a current of500 mA.

That is, when changing ST to the state USB3 (Task S67), the controller44 then turns the battery FET 37 ON (Task S68) and starts the quickcharge (Task S69). When acquiring the state USB3 from the controller 44,the system controller 64 then deactivates the power-on disabling section60 such that reception of the power key operation is enabled (Task S70).In this manner, the power-on section 58 is enabled to receive a requestfor power-on via the power key operation.

FIG. 9A is an illustration of an exemplary display content A (display A)on the screen of the display unit 4 according to an embodiment of thedisclosure. As illustrated in FIG. 9A, the display A presented duringthe pre-charge (first pre-charge) indicates a power-on disablednotification. The power-on disabled notification comprises messagesshowing: “BATTERY PRE-CHARGING” indicating that pre-charge is beingperformed, “Unable to power on” indicating that a request for power-oncannot be received, “Please wait” indicating that a user is prompted towait, and “--Power Off--” indicating that the mobile telephone 1 ispowered off. These messages can inform the user that power-on isdisabled and that the disabling of power-on results from pre-chargebeing performed. The message “Please wait” prompts the user to wait,thus reducing the possibility that the pre-charge is stopped by the userdisconnecting the adapter cable 101 or the USB cable 103 from theconnection terminal 20 during the pre-charge. The message “Please wait”notifies the user that if he/she waits for a certain period of timepower-on becomes available.

FIG. 9B is an illustration of an exemplary display content B (display B)on the screen of the display unit 4 according to an embodiment of thedisclosure. As illustrated in FIG. 9B, the display B presented duringthe quick charge comprises messages showing: “BATTERY CHARGING”indicating that charge is being performed and showing “--Power Off--”indicating that the mobile telephone 1 is not powered on. As describedabove, the display B illustrated in FIG. 9B does not contain “Unable topower on” in the display A illustrated in FIG. 9A. Therefore, the usercan be notified that power-on is available.

Contents of the display A and display B presented on the display unit 4are not limited to the content of display A illustrated in FIG. 9A andthe content of display B illustrated in FIG. 9B. For example, displayduring the quick charge may contain a message showing “Able to power on”indicating that power-on is available. The contents of display A and Bmay comprise, for example but without limitation, a graphicalrepresentation, a symbol, alphabets of various languages, and anycombination thereof.

FIGS. 10 and 11 illustrate state transition diagrams for charging of themobile telephone 1. FIG. 10 is an illustration of an exemplary statetransition diagram 70 for charging the mobile telephone 1 correspondingto the flow diagram of FIG. 6. FIG. 11 is an illustration of anexemplary state transition diagram 72 for charging the mobile telephone1 corresponding to the flow diagram of FIGS. 7 and 8.

In FIGS. 10 and 11, “OFF” in the column “DISPLAY” indicates a statewhere no display relating to charge is made on the display unit 4. “A”in the column “DISPLAY” indicates a state where the display Aillustrated in FIG. 9A is presented on the display unit 4. “B” in thecolumn “DISPLAY” indicates a state where the display B illustrated inFIG. 9B is presented on the display unit 4.

“OFF→A” in the column “DISPLAY” indicates that the display appearing onthe display unit 4 changes from the off state to the display A. “OFF→B”in the column “DISPLAY” indicates that the display appearing on thedisplay unit 4 changes from an off state to the display B.

An item containing an arrow “→” in FIGS. 10 and 11 indicates that, whenthe value of VBAT is within the range specified in the column, the statetransitions from a state located at the tail of the arrow to a statepointed by the tip of the arrow. A horizontal bar “---” indicates thatthe state does not transition.

FIG. 12 is an illustration of a graph showing an exemplary relationshipbetween the VBAT and time when ST is the WALL according to an embodimentof the disclosure. FIG. 13 is an illustration of a graph an exemplaryrelationship between the VBAT and time when ST is the USB according toan embodiment of the disclosure.

As described above, because the display A (FIG. 9A) is presented on thedisplay unit 4 during the first pre-charge, the user can be notifiedthat power-on is disabled. This notification allows the user to beinformed that power-on is available. Accordingly, under conditions whereit is difficult to stably power the mobile telephone 10N without causingthe user to suspect a breakdown, the occurrence of power-on made by theuser can be reduced, so usability of the charge process can be enhanced.

In the present embodiment, the notification indicating that power-on isdisabled is provided to the user by use of the display A appearing onthe display unit 4. The notification may be provided by use of the keyLED for the operation key unit 6.

For example, a color of emission from the key LED for the operation keyunit 6 may be yellow (emission color A) during the first pre-charge, andit may be red (emission color B) during the quick charge to provide thenotification accordingly. Other colors may also be used for suchnotifications. If the key LED is employed, the notification may beprovided by use of an emission from the key LED without turning ON thedisplay unit 4. Alternatively, the notification may be provided by bothemissions from the key LED and by presenting the notification on thedisplay unit 4.

Notifying means can also be any means other than visual means. Thenotifying means may appeal to at least one of the five senses such ashearing, touch, and the like. For example, notifying means for hearingmay be used alone, or in combination with any other notifying means. Inthis manner, the notification indicating that power-on is disabled maybe provided by a sound.

In an embodiment, a charge process by which charge is shifted from thepre-charge to the quick charge is described above where both processesuse constant currents. However, the charge process is not limited to theabove process. Other processes can also be used under conditions where avoltage is low such that it may be necessary to disable power-on.

In an embodiment, under normal conditions, the display A may not bepresented even during the first pre-charge. Upon activation or receiptof the press of an operation key of the operation key unit 6, thecontent of display A (display A) may be presented on the screen of thedisplay unit 4 for a predetermined period of time (e.g., approximatelyfive seconds). For example, the display A may be presented on the screenof the display unit 4 in response to activation of the power key 10.

In an embodiment, for charge during the USB connection, from the USBspecifications, the substantially maximum current that can be suppliedbefore a connection is established is about 100 mA and that after aconnection may be established the substantially maximum current may beseveral hundreds of mA (e.g., 400 mA).

Because of this, before a connection is established or when a connectioncannot be established, 100 mA is supplied. As such, the first pre-chargemay not be performed with a current of 80 mA. In these cases, even whenthe VBAT is equal to or greater than 2.8 V (2.8 V≦VBAT<3.2 V inquirybranch of task S43 in FIG. 7), the second pre-charge with the secondpre-charge current of about 40 mA may be performed (Task S44), and thedisplay A may not be presented on the screen of the display unit 4.

The first pre-charge current for the first pre-charge may be, forexample but without limitation, about 80 mA, and the like. The secondpre-charge current for the second pre-charge may be, for example butwithout limitation, about 40 mA, and the like.

During a USB connection, when a charging current (pre-charge current) ofthe rechargeable battery 22 is less than a current threshold value, thenotifying unit 64 does not provide the above notification. However, insuch a case, the above notification may be provided by a methoddifferent from a method used when the pre-charge current is equal to orgreater than the current threshold value. For example, when thepre-charge current is equal to or greater than the current thresholdvalue, the notification may be provided by presenting a message on thescreen of the display unit 4, and when the pre-charge current is lowerthan the current threshold value, the notification may be provide by useof the key LED. That is, a notification means requiring lower powerconsumption such as presenting a message on the display unit 4 may beused when the pre-charge current is equal to or greater than the currentthreshold value and a notification means requiring higher powerconsumption such as the key LED may be used when the pre-charge currentis lower than the current threshold value. The current threshold valuemay be, for example and without limitation, 100 mA and the like.

In this document, the terms “computer program product”,“computer-readable medium”, and the like may be used generally to referto media such as, for example, memory, storage devices, or storage unit.These and other forms of computer-readable media may be involved instoring one or more instructions for use by the processor/controller 44and/or the system controller 64 to cause the processor/controller 44and/or the system controller 64 to perform specified operations. Suchinstructions, generally referred to as “computer program code” or“program code” (which may be grouped in the form of computer programs orother groupings), when executed, enable an electronic device such as thecharge and discharge control system 200 of the mobile telephone 1.

While at least one exemplary embodiment has been presented in theforegoing detailed description, the disclosure is not limited to theabove-described embodiment or embodiments. Variations may be apparent tothose skilled in the art. In carrying out the disclosure, variousmodifications, combinations, sub-combinations and alterations may occurin regard to the elements of the above-described embodiment insofar asthey are within the technical scope of the disclosure or the equivalentsthereof. The exemplary embodiment or exemplary embodiments are examples,and are not intended to limit the scope, applicability, or configurationof the disclosure in any way. Rather, the foregoing detailed descriptionwill provide those skilled in the art with a template for implementingthe exemplary embodiment or exemplary embodiments. It should beunderstood that various changes can be made in the function andarrangement of elements without departing from the scope of thedisclosure as set forth in the appended claims and the legal equivalentsthereof. Furthermore, although embodiments of the disclosure have beendescribed with reference to the accompanying drawings, it is to be notedthat changes and modifications may be apparent to those skilled in theart. Such changes and modifications are to be understood as beingcomprised within the scope of the disclosure as defined by the claims.

Terms and phrases used in this document, and variations hereof, unlessotherwise expressly stated, should be construed as open ended as opposedto limiting. As examples of the foregoing: the term “including” shouldbe read as mean “including, without limitation” or the like; the term“example” is used to provide exemplary instances of the item indiscussion, not an exhaustive or limiting list thereof; and adjectivessuch as “conventional,” “traditional,” “normal,” “standard,” “known” andterms of similar meaning should not be construed as limiting the itemdescribed to a given time period or to an item available as of a giventime, but instead should be read to encompass conventional, traditional,normal, or standard technologies that may be available or known now orat any time in the future. Likewise, a group of items linked with theconjunction “and” should not be read as requiring that each and everyone of those items in the grouping be present, but rather should be readas “and/or” unless expressly stated otherwise. Similarly, a group ofitems linked with the conjunction “or” should not be read as requiringmutual exclusivity among that group, but rather should also be read as“and/or” unless expressly stated otherwise. Furthermore, although items,elements or components of the disclosure may be described or claimed inthe singular, the plural is contemplated to be within the scope thereofunless limitation to the singular is explicitly stated. The presence ofbroadening words and phrases such as “one or more,” “at least,” “but notlimited to” or other like phrases in some instances shall not be read tomean that the narrower case is intended or required in instances wheresuch broadening phrases may be absent. The term “about” when referringto a numerical value or range is intended to encompass values resultingfrom experimental error that can occur when taking measurements.

1. An electronic device comprising: a rechargeable battery; a chargingunit operable to: charge the rechargeable battery with a pre-chargecurrent when a voltage of the rechargeable battery is less than avoltage threshold value; and charge the rechargeable battery with acurrent that is larger than the pre-charge current, when the voltage ofthe rechargeable battery is equal to or greater than the voltagethreshold value. a disabling unit operable to disable power-on when thevoltage of the rechargeable battery is less than the voltage thresholdvalue; and a notifying unit operable to provide a power-on disablednotification, if the rechargeable battery is being charged with thepre-charge current and the pre-charge current is equal to or greaterthan a current threshold value.
 2. The electronic device according toclaim 1, further comprising a display unit comprising a screen andoperable to display the power-on disabled notification on the screen. 3.The electronic device according to claim 1, wherein the notifying unitis further operable to provide a battery charging notification toindicate that the rechargeable battery is being charged with thepre-charge current.
 4. The electronic device according to claim 1,wherein the notifying unit does not provide the power-on disablednotification, if the pre-charge current is less than the currentthreshold value.
 5. The electronic device according to claim 4, furthercomprising preventing display of the power-on disabled notification on ascreen of a display unit by not turning power on to the display unit. 6.The electronic device according to claim 1, further comprisingdisplaying a wait notification until power-on is enabled.
 7. Theelectronic device according to claim 1, further comprising providing abattery charging notification and/or providing the power-on disablednotification via sound.
 8. A method for charging an electronic device,the method comprising: charging a rechargeable battery with a pre-chargecurrent when a voltage of the rechargeable battery is less than avoltage threshold value; and charging the rechargeable battery with acurrent that is larger than the pre-charge current, when the voltage ofthe rechargeable battery is equal to or greater than the voltagethreshold value; disabling power-on when the voltage of the rechargeablebattery is less than the voltage threshold value; and providing apower-on disabled notification, if the rechargeable battery is beingcharged with the pre-charge current and the pre-charge current is equalto or greater than a current threshold value.
 9. The method for chargingan electronic device according to claim 8, further comprising displayingthe power-on disabled notification.
 10. The method for charging anelectronic device according to claim 8, further comprising providing abattery charging notification to indicate that the rechargeable batteryis being charged with the pre-charge current.
 11. The method forcharging an electronic device according to claim 8, further comprisingnot providing the power-on disabled notification, if the pre-chargecurrent is less than the current threshold value.
 12. The method forcharging an electronic device according to claim 11, further comprisingpreventing displaying of the power-on disabled notification on a screenof a display unit by not turning power on to the display unit.
 13. Themethod for charging an electronic device according to claim 8, furthercomprising providing the power-on disabled notification and/or thebattery charging notification via sound.
 14. A computer-readable mediumfor an electronic device, the computer-readable medium comprisingprogram code for: charging a rechargeable battery with a pre-chargecurrent when a voltage of the rechargeable battery is less than avoltage threshold value; and charging the rechargeable battery with acurrent that is larger than the pre-charge current, when the voltage ofthe rechargeable battery is equal to or greater than the voltagethreshold value; disabling power-on when the voltage of the rechargeablebattery is less than the voltage threshold value; and providing apower-on disabled notification, if the rechargeable battery is beingcharged with the pre-charge current and the pre-charge current is equalto or greater than a current threshold value.
 15. The computer-readablemedium according to claim 14, further comprising program code fordisplaying the power-on disabled notification.
 16. The computer-readablemedium according to claim 14, further comprising program code forproviding a battery charging notification to indicate that therechargeable battery is being charged with the pre-charge current. 17.The computer-readable medium according to claim 14, further comprisingprogram code for not providing the power-on disabled notification, ifthe pre-charge current is lower than the current threshold value. 18.The computer-readable medium according to claim 17, further comprisingprogram code for preventing displaying of the power-on disablednotification on a screen display unit by not turning power on to thescreen display unit.
 19. The computer-readable medium according to claim14, further comprising program code for providing a battery chargingnotification and/or providing the power-on disabled notification viasound.